Quick question. Apologies if it has been answered elsewhere. When I connect my phone to my car using Android Auto wirelessly, how is the signal moved from Roon ARC on the phone to the car?
Does the audio signal leave the phone at full bandwidth, and then get squished over Bluetooth to the car, and then rendered by the car’s system. Or does Android Auto move the whole signal, uncompressed, to the car, which then renders it out.
Hopefully that makes sense and thanks in advance.
Android typically downsamples to to 48 kHz. When connected to the car via cable, using Android Audio, this is unchanged.
However, wireless Android Auto streams over Bluetooth, which has a variable bit-rate up to a maximum.
For example, a 44.1 kHz CD has an equivalent bit-rate of over 700 kbps. In contrast, standard Bluetooth including aptX is up to 576 kbps.
But this is largely immaterial. Streaming lossless audio in a moving vehicle is an otiose undertaking since background noise means you cannot possibly distinguish one source from another.
Thanks for that. It’s what I thought. And I agree about SQ in moving vehicles! Was just curious about what’s actually going on. TBH, ARC is pretty clunky on Android Auto. I only really use it for some CDs that aren’t on streaming services (although there are fewer and fewer albums missing, in my recent experience).
Aren’t most CDs stereo though?
I was basing my calculations on Pet Sounds! 
No, you are correct, I forgot the times two.